The Salisbury Eye Evaluation study (SEE), initiated in August, 1992, has investigated the relationship between visual impairment and physical disability in a population-based cohort of 2,520 people 65-84 years of age. We have completed the baseline evaluation and two-year follow-up examination of our cohort. From these data we have shown that there are substantial age-related declines in multiple measures of visual function and that these declines are associated with increased physical disability, reduced social interaction, and self-perceived difficulties with daily visual tasks. We have broadened the scope of vision assessment, compared to previous population-based studies, by including tests of contrast sensitivity, glare, stereoacuity, and visual fields. These tests of static visual function account for 33% to 50% of the variance for some tasks, such as reading and face recognition, but are only weakly predictive of performance in other tasks, such as reading and face recognition, but are only weakly predictive of performance in other tasks, such as activities of daily living, driving and mobility. We propose to extend the SEE study by including two dynamic measures of visual function which laboratory studies suggest may be more closely related to certain aspects of physical disability, particularly those related to mobility. The new tests include dynamic visual acuity and a test of motion sensitivity based on the detection of a displaced random- dot image. We also plan to extend our previous work by specific addressing the interaction of vision loss with cognitive status. Cognitive status will be assessed with an extensive battery of tests measuring learning, memory, verbal fluency, and attention. Outcome measures will include questionnaires and performance-based tests of daily activities such as reading and navigating a mobility course. All surviving members of the original SEE cohort will be invited to participate in two additional rounds of testing, separated by a 24-month interval. Given current refusal and mortality rates, we expect 1,964 to finish Round 3 and 1,785 to finish Round 4 testing. This will provide an opportunity to evaluate prospectively the relationship between changes in vision and cognitive status, and changes in physical disability, all within the context of a population-based and racially diverse cohort of older adults.